The present invention relates to security systems and, in particular, to a system including one or more wireless keypad and distributed sensor or alarm transmitters, the identities of which transmitters are self-learned by the central processing unit (CPU) with an initial programming transmission.
Security systems including a plurality of distributed alarm sensors, of necessity, must be capable of distinguishing each sensor from each other sensor. For hard-wired systems, physical connections determine the identity of each sensor and dictate the inherent system response to detected alarm conditions. Wireless systems, in contrast, typically transmit with each transmission an identity code. This code is, in turn, decoded along with the alarm message by the CPU or central station as it responds to each received transmission.
An example of one such system can be found in applicant's U.S. Pat. No. 4,737,770 which discloses a system wherein the transmitter portion of each distributed wireless alarm sensor includes a programmable register which stores an installer-entered identification code. The code includes a "house code" or system defining portion and a "sensor number" defining the type of alarm sensor and zone protected within the system.
Otherwise, a variety of other predecessor systems have included DIP switches and other physically programmable devices which require installer intervention to make or break certain hardwired connections. Some systems have also included factory programmed memories.
Of necessity, however, the foregoing systems require the installer to manually maintain a record of the identities assigned to each sensor which must be individually, manually programmed into each sensor and into the system's CPU. Where the code is factory entered into the transmitter, the installer must still separately program each alarm sensor code into the CPU. Each code must further be confirmed after installation.
This programming process has been facilitated by way of Applicant's pending U.S. Pat. application Ser. No. 07/156,547, filed Feb. 16, 1988 and entitled Micro-Programming Security System. This system utilizes the programmable sensor transmitters of the U.S. Pat. No. 4,737,770 patent. Although, the sensor transmitters require manual programming in the field, the CPU is operable to self-identify its distributed sensors with the first transmission from each. Specifically, the CPU upon detecting a "house code" comparable to its own confirms whether the subsequently received identification code or sensor number has been programmed into a portion of RAM where predefined system data is loaded from ROM upon initialization. If not, the CPU flags the corresponding memory location in RAM and thereafter knows the identity of each of its reporting wireless sensors.
Although the foregoing CPU is capable of learning its sensors by flagging predefined sensor numbers, an installer may inadvertently still mis-program one or more sensor identification numbers. While relatively easily detected for systems with relatively few distributed sensors, for larger commercial installations, it becomes much more difficult and time-consuming to detect errors.
Accordingly, a need exists for an apparatus and a methodology whereby the human element can be removed from the process of defining and setting sensor identity codes at the keypad, each alarm transmitter and the CPU. This will not do away with the installer though, since he/she need always insure the proper installation and operation of the alarm detecting transducers associated with each sensor transmitter, among the other tasks normally performed by such personnel.